Halogen containing resin stabilized with an acetylene alcohol



Patented July 15, 1952 .HALbGllN-CONTAINING RESIN STABILIZED WITH AN,ACETYLENE ALCOHOL I -jjHeinrich Berger and Roland Linke,

Weinheim-Bergstrasse, Germany summing. Application September 28, 1949,

Serial No. 118,462, In Germany October 1,

The present invention relates to im ticmasses. fi'

In the processing of plastic masses, which gencrally is carried out inthe heat, corrosion often occurs in the metallic, especially in theiron, parts of the apparatus employed, for instance of the rollers andmolds used. These corrosion phenomena are obviously'due to slightdecompositions taking place when working certain plastics or whencoemploying certain addition or assistant products, whereby corrosivesubstances, especially those of an acid nature, such as hydrogenchloride, acetic acid or other acids are formed. Such plastics are, forexample, high-polymer substances containing halogen atoms, such aspolymerisation or interpolymerisation products of vinyl chloride,vinylidene chloride, vinyl and acrylic acid esters and cellulose esters.To meet this inconvenience, additions to the plastic masses of so-calledstabilizers have been suggested, e. g. substances which are to repressor inhibit the decomposition. While proved plasthese substances exert aremarkable stabilizing action in many cases, they are not able toprevent satisfactorily the corrosion of metals coming in contact withplastic masses at elevated temperatures.

The object of our present invention is to provide a composition ofmatter which is free from these difliculties and can be processedwithout causing corrosions on metal, in particular iron, parts of theapparatus employed therefor.

We have found that the corrosion effect of plastic masses on metals, inparticular on iron, can be overcome by the addition of even a smallpercentage of a hydroxy compound having a triple bond between two carbonatoms, e. g. of an acetylene alcohol or of an oxalkylation productthereof, for example of propargylic alcohol, 1.4-butinediol and the likeor their hydroxyalkyl ethers, e. g. hydroxyethyl ethers orpolyhydroxyethylation products. The presence in plastic masses of thesetriply unsaturated hydroxy compounds not only has the effect ofpreventing corrosion of the metal, especially the iron, parts of theapparatus, e. g. iron molds or rollers, used in the processing of thesaid plastic masses, but to re-establish also the initial polish of suchmetal parts, when these had been slightly corroded by previous contactswith corrosive plastic masses.

In some cases also the addition of the said unsaturated hydroxycompounds may allow of using such substances as were heretoforeinapplicable for their highly corrosive properties.

Claims. (01. zen-45.95)

Thus, for example, it is the common practice in the making of porousplastic masses to add socalled expanding agents, i. e. substances whichundergo decomposition in the heat thus forming gases and which expandthe material by the action of the gases liberated. Widely known as asubstanceof this 'type and which, by adding cheapness to the capacity offorming an abundant amount of gas on decomposition, would make asuitable expanding agent for plastics, is ammonium nitrite. Being highlyunstable, it maybe used in the form of an equimolecular mixture ofsodium nitrite and an ammonium salt, for instance ammonium chloride,ammonium sulfate or ammonium carbonate. Ammonium nitrite, however, whileacting satisfactorily as an expanding agent, cannot be used in manycases, as it is liable to cause strong corrosions.

in the molds. No corrosion, however, occurs when plastic materials inwhich ammonium nitrite has been incorporated as an expanding agent, areadmixed with a slight percentage of a hydroxy compound having a triplebond between two carbon atoms. Ammonium nitrite is, therefore, no longerobjectionable as an expanding agent for plastics.

In practical use, the said unsaturated hydroxy compounds are applied,preferably, in amounts ranging from 0.05 to 3 per cent, preferably from0.25 to 3 per cent (percentage with reference to the weight of theplastic material), but larger percentages may also be employed.

The following examples serve to illustrate the nature of this invention,but the invention is not intended to be restricted to these examples.The parts are by weight.

Example 1 1000 parts of a polymer of vinylidene chloride or of acopolymer of vinylidene chloride and vinylchloride, in whichplasticizers may be incorporated, are laminated on iron rollers, atelevated temperatures, after the addition of 1 part of 1.4-butinediol,and the laminates obtained are pressed to form foils or plates. Evenafter prolonged use the rollers and molds show no marks of corrosion,whereas in the absence of butinediol the iron parts of the apparatusused would be attacked within a short time. Owing to the corrosion whichordinarily iron is liable to suifer by contact especially withvinylidene, it was hitherto inapplicable in the construction of rollersand molds in which such polymers were processed, and specialnon-corrosive steels had instead to be used.

Example 2 1000 parts of plasticized cellulose acetate are homogeneouslymixed with 2 parts of propargylic alcohol and made up in known manner toform an injection-molding material. While no corrosion is caused by thismixture when injected into the molds, some slight corrosion will occurupon the polished iron parts of the molds through the contact for somelength of time with the same type of plasticized cellulose acetate.when.

no propargylic alcohol has been added.

Instead of propargylic alcohol the oXyethyl ether thereof may beemployed with' the'same success.

Ewample 3 50 parts of polyvinyl chloride, 50 parts of dibutylphthalate,6.9 parts of sodium nitrite, 5.3 parts of ammonium chloride and 0.4 partof butinediol are homogeneously intermixed and heat-pressed in a moldofordinary steel, porous shapes being obtained. Even after several Weeksservice the steel-mold does not appear to be stained by corrosion,whereas the polish of the mold gets seriously marred already when twice"contactedwith the same mass to which, however, no butinediol had beenadded.

What we claim is:

. 1. A composition of matter comprising a high* polymer substancecontaining halogen atoms, and

asmallamount ofa hydroxy compound having a triple linkage between twocarbon atoms.

. 2.- A compositionfof matter comprising a high- ,polymer substanceconsisting at least in part of polymerized vinyl chloride and asmallamount of 'propargylic alcohol.

5. A composition of matter comprising a highpolymer substance consistingat least in part of Ipolymerized vinylidene chloride and a small amountof an acetylene alcohol.

6. A composition ofmatter comprising a highpolymer substance consistingat least in part of polymerized vinylidene chloride and a small amountof 1.4-butinediol.

'7. A composition of matter comprising a highpolymer substanceconsisting at least in part of polymerized vinylidene chloride and asmall amount of propargylic alcohol.

HEINRICH BERGER. ROLAND LINKE.

REFERENCES CITED The following references are of record in the file ofthis patent:

' FOREIGN PATENTS Country Date Germany Nov. 12, 1943 Number

1. A COMPOSITION OF MATTER COMPRISING A HIGHPOLYMER SUBSTANCE CONTAININGHALOGEN ATOMS, AND A SMALL AMOUNT OF A HYDROXY COMPOUND HAVING A TRIPLELINKAGE BETWEEN TWO CARBON ATOMS.